Following the events of their trip to Okinawa, Saitama University graduate students Shinya Yukimura and Ayame Himuro have failed to obtain the data necessary to scientifically prove their love for each other. Unable to replicate the exact conditions of the trip, the two stubborn scientists decide to seek help from elsewhere in the university—the Biological Sciences department. Assisted by fellow graduate students and longtime couple Chris Floret and Suiu Fujiwara, Yukimura and Himuro begin to quantify their feelings by measuring their output of oxytocin in various romantic situations. The two scientists soon find that their feelings for each other are nothing compared to that of a mature couple. It is here that Chris poses a question to both Yukimura and Himuro: what will they do if their affection is proven not to be love after all? Desperate to find a scientific rationale for the discrepancy, Yukimura puts everything on the line to prove that their love is real.

Remy, a cheerful and tender-hearted girl, lives with her mother in a French country town. One day her father returns to the town after a long period working away from home in a city. Her father tells Remy that she isn't their real daughter, and Remy is almost sold to an evil slave trader. It is Vitalis, a strolling entertainer, who helps Remy. Vitalis discovers her talent for singing and decides to take her in with his troupe. (Source: ANN)

Brothers Lucifer, Mammon, Leviathan, Satan, Asmodeus, Beelzebub, and Belphegor are among the most powerful demons in the Devildom, serving as officers on the student council at the Royal Academy of Diavolo (RAD). However, being avatars of the seven deadly sins, their behaviors often tend toward the extreme. Their everyday antics belie their high status and fearsome reputations among others of their kind. When viewed behind the scenes, the members of this family are more lovable—and laughable—than they first seem!

Under the belief that the omnipotent god Mitama will come to save him, Yukito Urabe participates in a ritual to become the new leader of his father's cult. But when the boy drowns during the ritual, he wishes to be reborn in a world without gods or religion. Reawakening in a completely different world devoid of spirituality. He meets a deviant girl named Aruaru, who introduces him to her village. However, his idyllic image of this world's society is short-lived when he witnesses a public group suicide and learns of the country's end-of-life system: at any moment, the government may order any citizen to die. Aruaru and her sister are forcibly taken for execution soon after, prompting Yukito to rush to their rescue—but to no avail. In a moment of desperation, Yukito recalls his father's teachings and utters a prayer for Mitama to save them. Seemingly answering his call, a little girl descends from the sky and annihilates everyone who harmed Yukito and his friends. To Yukito's surprise, the girl introduces herself as Mitama.